I think Zhao has the largest contribution out there, offering a decent centralized exchange that moved as much away from KYC as possible while making their platform not only newbie-friendly but a very attractive way of bringing in new inevstors into the game..
It seems to me that Zhao is more of a typical Chinese businessman than a technological contributor. My respect goes out more to, say, Vitalik Buterin than CZ. When Binance came out, it was very obvious that it was made 99% for money and 1% for providing an alternative and competitive platform for cryptocurrency traders. The latter being offered primarily for the sake of the former.
I noticed how CZ is coming up with so much products but it seems none of them is a breakthrough. They're more or less polished products with a personal touch of CZ but were all copied from earlier and original versions. CZ has his own CEx, DEx, P2P exchange, blockchain, DeFi, DApps, staking platform, IDO launchpad, crypto data site when he purchased CMC, now NFT, and so on and so forth. However, which among these is CZ's original contribution to cryptocurrency development?
But the guy earned my respect.